Teat cup of milking machines



Jan. 5, 1932.

.1. R. KNox TEAT CUP OF MILKING MACHINES Filed Nov. 19, 1929 F/GJ.

Patented Jan. v5, 1932 rss JGSEPE ROGERS KNDX, OF EEAENG, HGLAIEIID, ASSIGNR F ONE-i GEORGE HARRY GASCOGNE, OF QEENSF'EERE, bVGKNGHAIi-, 'IBERKSHREL ENGLAND naar our 0F ivrfLKine iaaonivns Application. filed November 19, 1929, Serial N. 203.323, and in Great Britain December 7, 1923.*v

' rlhis invention relates to teat cups for use in association with milking machines, and refers more especially to such devices of the kind comprising a rigid shell or casing with a flexible liner and wherein the interior of the liner is subjected to suction and the space between the casing and the liner to pulsations of pressure or suction. p f

l/Vhen the same degree of vacuum exists on both sides of the liner the liner remains in the cylindrical form. `When the vacuum (or partial vacuum) exists inside the liner and atmospheric pressure is admitted to the outer space the liner collapses or ilattens, thereby squeezing the teat of the cow being niilked.

lt has been found as would be expected, that the liner when new flattens along the diameter which offers the least resistance to collapse, and henceforth continues at each pulsation to flatten along this particular diameter.

The bottom end of the liner as in the case of tensioned liners, is held permanently in circular shape by one of the various arrangements used for the clamping of the liner'to the rigid shell. In the case of non-tensioned liners similar to that described in Patent Specification No. 285,233, the bottom end of the liner is held in circular shape by the thick walled milk tube, which is formed in one piece with the liner.

From the foregoing it will be seen that the collapsing of the liner takes place between the point where the cows teat holds the liner in circular form and the bottom end of the liner and the most severe bending stress is set 11p-between these two points. It is between these two points that the cracking occurs.

rlhe object of the present invention is to provide a means whereby the diameter along whichthe flattening -or collapsing takes place may frequently be changed, thereby preventtie stressing of the liner being localized at two opposite points yon the circumference.

According tothis invention, therefore, a teat cup isprovided in which the flexible liner is adapted to flatten or collapse along a diameter determined by the relative positions of the 'said liner and the outer rigid shell. Y

`This is preferably effected by forming or providing the said outer rigid shell with means for producing an initial or partial flattening ofthe flexible liner when the latter is operatively engaged therein and such means may take the form of two flats or indlenltlations formed in opposite sides of said s e When the liner is in the uneollapsed form these flats or indentations press on the walls of the liner and constrain it to assume a shape of oval cross-section over part of its length, usually at'a suitable point` below that to which the cows teat extends within the liner when thekte'at cup is in operation. When the liner is in this shape it-is found that it will collapse along the major axis of the oval.

A teat cupconstructed in accordance with the invention will now be more fully described with reference to the accompanying drawings, wherein Fig. l is a longitudinal section of the teat cup and V`Fig. 2 is a horizontal section thereof taken on the line 2-2 of Fig. l.

In` the drawings the outer rigid shell a is shown asI fitted with a flexible liner Z) of the kind described in Patent' Specification No. 285,233, the lip @formed on the upper end of the liner` taking over the upper end of the shell or casing a and the lower end d of the liner forming a close push fit in the opening at the lower end of the casing.

At a suitablefpoint below the end of the cows teat (not shown) two flats or indentations e, e are formedvin the wall of the shell a on opposite sides, these flats e pressing on the liner b when it is in the uncollapsed form and forcing it to assume a shape of r approximately oval cross-section (see `Fig. .2). As will be `understood the liner, when in this shape, will collapse *along the major axis of the oval.

Now each time the liner is taken outrof the shell a and afterwards replaced the chances are very much in favor of it being replaced in the shell in a diiierent posit-ion in relation to the two flats or indentati-ons e on the shell. The oval cross-section will then be formed each time so that its major axis runs a different way, and it will therefore be apparent that the stressing of the liner will be distributed all round the circumference.

Instead of two flats e being formed on the outer rigid shell 05,., the shell may be made in any form which will constrain the liner to assume an oval or similar cross-section when in the unflattened state.

This invention is applicable .-to'teat -eups with liners of the tensioned type las well as to liners of the nontension type such as illustrated. l

I claim 1:7 Y

l. A teat cup for use in association with milking machines comprising a rigid shell, a collapsible flexible `liner disposed within said shell and adapted to engage by -an upper unrestricted portionV of its length over 'the Vteal; being milked, and fixedly disposed inwardly extending portions on said shell contacting over a comparatively-small area with a lower portion of the liner in order to impartan initial flattening thereto in the direction in which said liner is to collapse during the milking operation.

2. A teat cup of theclass described com-v prising a rigid shell, a collapsible flexible liner disposed within said shell and adapted to engage by an upper unrestricted portion of its lengthover the teat 'being milked, and indentations -in said shell providing-inwardly extending yportions each engaging the said liner overa comparatively small area, at a point below that to which the 'teat extends within the liner, in order to impart fan,

initial flattening to the said liner-'in the direction in which the saine'is to collapse during the milking operation.

3. A teat cupyof the class described comprising a rigid shell of substantially cylindrical form, a collapsible flexible liner disposed within said shell and adapted to be heldin substantially cylindrical form at its upper end by the insertion therein of the'teat to be milked, means for holding the lower end of said liner in substantially cylindrical form, and diametrically opposed flats formed inthe rigid shell so that they engage therliner between the ends thereof, over a comparatively sinallarea,-and impart a slight flattening to said liner, belowthe point to which the teat weaves extends therewithin, in that direction' in which the liner is to collapse during the milking operation.

el. A teat cup of the class described coinprising a rigid shell of substantially cylindrical form, a collapsible flexible liner disposed withinsaid shell, an upper unrestricted portion of said liner held in substantially cylindrical form by a teat inserted therein, a lower portion of said liner adapted to be collapsed, means holding the lower end of said lower portion in substantially cylindrical form, and indentations formed in the rigid shell to produce diametrically opposite Hats in the interior thereof adapted to engage the lower portion of the flexible liner over a comparatively small area andfproduce a slight initial flattening of the liner in .that direction in which said liner is to collapse during the milking operation.

In testimony whereof he has affixed his signature.

JOSEPH ROGERS KNOX. 

